ES2672807T3 - Manual drive sharpener - Google Patents

Abstract

A manually operated sharpener (14) comprising a base (52), a hollow housing housing (54) mounted on said base (52), an extension of the housing (55) above said base (52), a guide surface (58) in said extension of the casing (55), characterized in that it further comprises a carousel (60) in said extension of the casing (55), said carousel (60) has a rotating cylinder (68), a first abrasive pad (70, 72) mounted on said cylinder (68), a second abrasive pad (70, 72) mounted on said cylinder (68), the rotation of said cylinder (68) selectively disposes each of said first pad abrasive pad (70, 72) and said second abrasive pad (70, 72) adjacent to said guide surface (58), and each of said first abrasive pad (70, 72) and said second abrasive pad (70, 72) differs one from another in abrasive characteristics.

Description

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DESCRIPTION

Manual drive sharpener Background of the invention

There are several types of specialized sharpeners to meet the needs dictated by the different types of cutting instruments or other tools that must be kept in a sharp state. There are times when it would be desirable to have multiple sharpeners available. An example is the use by fishermen where a knife sharpener is desired to sharpen a knife that could be used in the filleting of a fish. Another type of sharpener that could be desired is a scissors sharpener for cutting lines such as line snipers. An additional sharpener may be desirable to maintain a hook in a sharp condition.

It would be advantageous if different types of sharpeners, such as those desired by a fisherman, could be included as a common sharpener assembly so that individual sharpeners are available conveniently and easily. Such a concept of providing multiple sharpeners could also be used in situations where it would be useful to have multiple sharpeners mounted as a combination where the sharpeners are not the specific combination of knife sharpeners used with scissors sharpeners and hook sharpeners.

An additional consideration, as for fishermen, is that when one of the sharpeners, such as the knife sharpener, is electrically powered, an AC power source may not be readily available. Therefore, the fisherman would have to do the actual sharpening of a knife in a distant inconvenient place.

Attention is drawn to US Patent 6 846 229 B1, which represents the prior art closest to the subject matter of claim 1 and shows a retractable knife sharpener having an ergonomically sized handle with an internal recessed portion and an opening at one end thereof in communication with the recessed portion and a sled slidably received within the recessed portion and has an outer end with a sharp blade structure and an interior end and selectively positionable, with respect to the handle , between a retracted position and an extended position that exposes the knife sharpening structure.

Summary of the invention

An object of this invention is to provide a hand operated sharpener according to the appended claims. The hand-operated sharpener, also called manual sharpening module in the following description, is preferably a scissors sharpener that has its housing removably mounted in a recess in the housing of the electric sharpening unit. Preferably, the manual sharpening module includes a rotating carousel having a coarse abrasive sharpening pad and another fine abrasive pad mounted opposite with a thumb wheel that controls which pad would be directed towards the guiding surface on which the blade is placed. scissors. The abrasive pads are preferably mounted on a threaded-coupled carousel cylinder with a threaded vertical rod to change the area of the pad used in sharpening.

Figures:

Figure 1 is a perspective view looking down a combination sharpener assembly showing the electrically driven sharpening unit (knife sharpener) not covered by the scope of the present invention and the manual sharpening module (sharpener of scissors) in accordance with the present invention and the battery operated sharpening component (hook sharpener) not covered by the scope of the present invention;

Figure 2 is a perspective view looking up from the assembly of Figure 1;

Figure 3 is a front elevation view of the electrically driven knife sharpening unit of the assembly of Figures 1 and 2;

Figure 4 is a rear elevational view of the electrically driven knife sharpening unit of Figures 1 and 3;

Figure 5 is a top plan view of the electrically driven knife sharpening unit of Figures 1 and 4;

Figure 6 is a bottom plan view of the assembly of Figures 1 and 2 showing both the electrically driven knife sharpening unit and the scissors manual sharpening module sharpening module;

Figures 7 and 8 are extreme elevational views of the housing of the electrically driven knife sharpening unit of Figures 1 and 2;

Figure 9 is a cross-sectional view taken through Figure 5 along line 9-9;

Figure 10 is a cross-sectional view taken through Figure 5 along line 10-10;

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Figure 11 is a plan view of the housing of the electrically driven knife sharpening unit of the assembly of Figures 1 and 2, without the manual scissors sharpening module;

Figure 12 is a perspective view looking upwards of the housing of the electrically operated knife sharpening unit of Figures 1 and 2, without the manual scissors sharpening module;

Figure 13 is a perspective view of the manual scissors sharpening module according to the present invention in the assembly of Figures 1 and 2;

Figure 14 is a front elevation view of the manual scissors sharpening module of Figure 13;

Figure 15 is a rear elevational view of the manual scissors sharpening module of Figure 13;

Figure 16 is a top plan view of the manual scissors sharpening module of Figures 13 to 15;

Figure 17 is a cross-sectional view taken through Figure 16 along line 17-17;

Figure 18 is an assembly view of the manual scissors sharpening module of Figures 13 to 17;

Figure 18A is a perspective view of the carousel used in the manual scissors sharpening module of Figures 13 to 18;

Figure 18B is a side elevational view of the carousel shown in Figure 18A;

Figure 19 is a perspective view showing the use of the manual sharpening module of Figures 13 to 18 to sharpen scissors;

Figures 20 to 22 are cross-sectional views of manual sharpening modules of alternative scissors in accordance with this invention; Y

Figure 23 is a block diagram showing the printed circuit board used to start the motor of the electrically driven knife sharpening unit in the assembly of Figures 1 and 2.

Detailed description

Figure 1 shows a combination sharpener assembly 10 when viewed from the top. Figure 2 shows assembly 10 when viewed from the bottom. As shown therein, assembly 10 includes an electrically actuated sharpening unit 12 that has at least one sharpening stage with at least one sharpening element in the sharpening stage. Preferably, the sharpening unit 12 is a multi-stage knife sharpener.

The assembly 10 also includes a manual sharpening module 14 which is removably mounted to the housing of the electrically operated sharpening unit 12. Preferably, the sharpening module 14 is a scissors sharpener.

An additional sharpening module in assembly 10 is an electrically operated sharpening component (battery) 16 that could be used by fishermen to sharpen their fishing hooks. The electrically operated sharpening unit 12 is a knife sharpener that can be operated in a manner similar to the sharpeners shown in US Pat. Nos. 5,611,726, 6,012,971 and 6,875,093, all details of which are incorporated by reference herein. Figure 9 best illustrates the main components of the knife sharpener 12. As shown therein, a motor 18 rotates its stem 20 to drive the gear train 22. The gear train 22 drives the sharpener rod 24 in which sets of 26,28 coated abrasive discs are mounted in each of the sharpening steps in a manner known in the art. A retaining spring 30,32 is provided at each stage so that a knife can be inserted against a guide surface 34, 36 at each stage and directed against the rotating abrasive disk 26,28. Thus, when a cutting instrument, such as a knife, is placed against the appropriate guide surface 34,36 and pushed into contact with the rotating sharpening element or abrasive disk, the knife is sharpened in a known manner .

The knife sharpener housing 12 includes special features designed to accommodate other types of sharpeners and to perform other functions. For example, the motor 18 is located in a chamber of the housing or in the internal motor 38, in the motor section of the outer housing of the knife sharpener. One of the characteristics is to prevent or limit the motor 18 so that it does not come into contact with water. This is particularly important when the knife sharpener 12 is used at a fishing site where there could be splashing water or where the fisherman may wish to hose the sharpener with a hose. In order to provide this generally sealed chamber, the chamber is formed by a perforated cover 40 above the housing of the non-perforated chamber 42. Sealing elements are provided, such as seals 46 where the cover 40 and the chamber housing 42 come into contact with each other. A seal of the seals also seals where the sharpening rod 24 enters the engine chamber 38. The seals would also seal the fixing screws to the motor cover. In addition, when the cover of the power port 124 described more

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Forward (Figure 2) closes, it would seal the feed port 122. These seals prevent water from entering the engine chamber 38 and coming into contact with the engine 18.

The outer housing for the knife sharpener 12 is generally formed from two housings, the upper housing 48 and the lower housing 50. If desired, a sealing material could also be provided, such as gaskets, where These housings are joined together.

The manual sharpening module 14 according to the present invention, which operates without the use of any motor unit is preferably a scissors sharpener that is mainly illustrated in Figures 13 to 22 and is also shown in other figures.

The manual sharpening module or scissors sharpener 14 includes a base 52 for resting on a support surface, such as a table. A generally triangular shaped housing 54 extends upwardly from the base 52. The base 52 and the housing 54 forms a hollow housing having an open bottom. The sharpening components are located in the narrow extension 55 of the housing 54. The housing 54 is provided with a series of longitudinal grooves 56 so that the housing 54 can be easily grasped and functions as a handle, especially for squeezing housing 54 as described below. The extension 55 of the housing 54 above the base 52 has an open area with a flat surface 58 that functions as a guide surface. A carousel 60 is mounted on the extension 55 adjacent to the guide surface 58. The carousel 60 includes a non-circular base 62 that fits into a complementary opening 64 of the thumbwheel 66. See Figure 18. The carousel 60 includes a cylinder 68 extending upwardly from base 62. Cylinder 68 has a pair of flat surfaces 75 where abrasive pads 70, 72 are located above flange 69. A threaded rod 74 extends through an axial opening 76 in the cylinder 68 and threadedly engages an internally threaded axial opening 79 of the insert 78 pressed into the opening 76 of the cylinder 68. See Figures 17 and 18. The upper end of the rod 74 fits into the sleeve 77 of the housing extension 55.

The thumb wheel 66 includes marks such as the word "thick" and "thin" to correspond to the pads 70, 72. When the thumb wheel 66 is rotated, a corresponding abrasive pad 70 or 72 could be arranged on the surface of guide 58 and the marks on thumb wheel 66 indicating whether it is a thick abrasive pad or a fine abrasive pad that is used for the sharpening operation.

As best shown in Figures 18A and 18B, the cylinder 68 includes a lower circular flange extending outwardly 69 and an upper circular flange extending outwardly 71. Each flange 69.71 is provided with a set of parallel grooves 73 on the upper surface of the flange 69 and smaller surface of the flange 71 located adjacent to the flat sides 75 of the cylinder 68. See also Figure 18. Each respective abrasive pad 70, 72 is inserted into a set of the grooves upper and lower adjacent to the respective flat side 75 of the cylinder 68 to mount each pad in a flat condition. By having the upper slots and the lower slots out of phase or offset from each other (Fig. 18B), the angular orientation of the pads 70, 72 differs from each other. A set of grooves can be aligned vertically to maintain its perpendicular pad.

The carousel 60 thus allows different abrasives and different angles to be integrated into the unit. The stages can be changed by the user simply by rotating the cylinder 180 °. The abrasive cartridge may contain at least one coarse diamond abrasive pad at an angle between 70 ° and 85 °. This provides a raw rejuvenation for well worn scissor blades. The user can then rotate the carousel 60 to the fine stage which has at least one finest diamond abrasive pad at an angle between 80 ° and 90 ° to put a thin edge on the scissor blades. The carousel 60 can be turned by hand by the use of the thumbwheel 66 protruding from the front part of the sharpener 14. This is an improvement over existing designs that may have only one sharpening stage or are more difficult to change. between the stages of sharpening.

In use, as shown in Figure 19, the blade 80 of a scissors 82 would be placed on the guide surface 58 and disposed against an abrasive pad. Due to the configuration of the cylinder 68 having flat sides and by means of mounting the pads in the grooves 73, the abrasive pads 70, 72 are oriented in a flat flat condition instead of being wrapped in a curved condition. The blade 80 or each side of the scissors 82 are sharpened independently simply by placing the inside of the blade against the guide surface 58 and the movement of the blade in a reciprocating motion against abrasives that are preferably particles of diamond Precision angle control is achieved because the scissor blade is easily maintained against the guide of the flat blade 58, and the angle of the abrasive is maintained by the sharpener. This is an improvement over existing manual sharpeners, where the user must properly hold and close the scissors on a ceramic abrasive stick, as shown in US Patent No. 6,101,898 or a metal polishing element, such as It is shown in U.S. Patent No. 5,001,945. The closure of the two scissor blades consisting of the abrasive stick can be difficult for some users and lead to poor sharpening results. The movement of the sharpener 14 is also more intuitive, since the sharpener can rest on a work surface, such as a table, with the base 52 of the sharpener directly on the support surface and the blade is guided in a very easy and obvious.

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The design of the carousel 60 allows the abrasive pads 70, 72 to remain constantly parallel to the edge of the blade even when the user can vary the angle of the blade in the sharpener slightly. The design allows the carousel 60 to rotate freely, so that the pressure of the scissor blade keeps it aligned. Since abrasive pads 70 or 72 can constantly follow sheet 80, they can better provide a sharp and consistent edge evenly. It also provides even wear on the abrasive pad 70, 72. This is an improvement over existing designs where the user must be careful to keep the scissors so that the blade edge is constantly in contact with an abrasive pad or models They use an abrasive rod whose contact point can lead to an uneven edge.

An additional feature of the sharpener 14 is that it allows the abrasive pads 70, 72 to move vertically during normal use in order to vary the abrasive surface that is used. All abrasive surfaces used for sharpening wear out over time. Wear is accelerated in some previous designs since the same small area of the abrasive pad or rod is used with each sharpening. With the sharpener 14, however, the area of the abrasive pad that is used changes as the cylinder 68 is rotated to change stages. As shown in Fig. 17, the threaded rod 74 is coupled with the lower flange 69 for the movement of the cylinder 68 vertically upwards or downwards according to the movement of the thumbwheel 66. Therefore, with each turn of the cylinder 68, the pads 70, 72 move up or down a small amount, due to the tilting of the cylinder 68 on the threaded rod 74 during use.

The manual scissors sharpener 14 is uniquely compact in design and is capable of sharpening scissors effectively by maintaining a precise sharpening angle against an abrasive pad. The sharpener 14 is capable of multiple stages of sharpening due to its carousel design that is capable of using different sizes and levels of abrasives at different sharpening angles.

In the illustrated embodiment of this invention, the carousel 60 has two flat faces 75 in the cylinder 68 to accommodate a respective abrasive pad 70, 72. In this way, the user can selectively focus a scissor blade by using a coarse or fine diamond abrasive pad. The invention can also be practiced where the cylinder 68 has more than two flat sides, such as four sides, each with a corresponding abrasive pad that can have its abrasive characteristics between thin and thick and thereby accommodate different sizes of Width set at different angles for a variety of different scissors. When additional abrasive pads are used, additional sets of grooves are also provided in the flanges 69, 71 of the carousel 60 to accommodate the additional abrasive pads.

Figures 20 to 22 show other variations of the scissors sharpener. As shown in Figure 20, the scissors sharpener 14A has a magnet 84 located below the guide surface 58 to attract a scissor blade in order to better maintain a constant angle for the custom scissor blade That the leaves are sharpening. Alternatively, or in addition, abrasive pads 70, 72 can also be magnetized to ensure better contact with the sharp edge.

Figure 21 shows an additional alternative sharpener 14B in which a retaining spring is mounted on the inner surface of the extension 55 of the housing 54. The spring has a spring arm 86 extending towards, but slightly spaced from, the guide surface 58. The retaining spring may be made of any suitable elastic material, such as a flexible plastic member to hold the scissor blade in place against the guide surface.

Figure 22 illustrates yet another variation of the invention in which the sharpener 14C has a wedge 88 mounted on the surface 58 to provide a substitute guide surface with a modified angle against which the scissor blade would be arranged to guide the blade of the scissors in contact with the abrasive pad. Thus, the sharpener 14C accommodates scissors with a knife edge in which the wedge will hold the scissors at a modified angle that is unique to scissors with a knife edge. Preferably, the wedge 88 is a removable insert that can be replaced by other inserts having different geometry. An additional variation would be to structure the wedge as an adjustable insert so that variations in the guide angle can be achieved without having to remove one insert and replace it with another. Any suitable means can be used to provide such adjustability, such as by mounting the insert on a threaded member that extends through the guide surface 58 to raise or lower the insert and alter the orientation of the insert.

Advantageously, the scissors sharpener 14 is removably mounted to the housing of the knife sharpener 12. Reference is made to Figures 2 and 11 to 13 with respect to how to detachably mount the scissors sharpener 14 to the sharpener of knives 12 so that both sharpeners can be stored together and readily available for the use of each sharpener. As shown in Figures 2, 11 and 12, the housing of the lower housing 50 for knife sharpener 12 includes a recess 90 on its lower side. A set of slots or openings 92 is provided in separate places in the recess 90. See Figures 11 and 12. The base 52 of the scissors sharpener 14 includes a corresponding set of locking tabs or projections 94 positioned for insertion into the slots. respective 92. The hollow housing 54 and the base 52 of the scissors sharpener 14 are rigid, but sufficiently elastic so that their opposite walls can be tightened, which would move the projections 94 in a sufficient distance such that after cessation of the compression action, the projections 94 move outwardly for engagement in the grooves 92. This mounts

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firmly the scissors sharpener 14 in the knife sharpener housing 12. When it is desired to remove the scissors sharpener, the housing 54 is pressed again to remove the protrusions 94 from the grooves 92 such that the scissors sharpener 14 is can withdraw easily. Therefore, the walls of the recess 90 function as a storage member for the sharpener 14.

As shown in the various figures, the lower housing 50 of the outer housing for the knife sharpener 12 has a plurality of feet extending below the periphery of the housing to raise the housing above a support surface. As illustrated, the stored scissors sharpener also rises above the support surface. A set of feet 96, 96 may be generally cylindrical in shape made of a rubber or other material that does not damage the support surface. The other set of feet 98, 98 may include suction cups to hold the knife sharpener housing in place during use. If desired, all feet may include suction cups or suction cups may be omitted. As shown in Figures 3 to 4, 7 to 8 and 10 the feet of the suction cups 98 extend downwardly from the bottom of the housing a distance slightly greater than the rubber feet 96. When, however, the suction cups are pressed Against the support surface, both sets of feet will extend down the same distance.

The assembly of the combination sharpener 10 not covered by the scope of the present invention may also include a third sharpener, namely the hook sharpener 16 best shown in Figures 1 and 2. As shown therein, the Hook sharpener 16 includes a generally cylindrical hollow case 100 to maintain a suitable number of batteries 102 to energize the drive mechanism 104 at the removably mounted operating end 106 of the sharpener 16. The drive mechanism 104 is actuated by pressing the switch 105. A sharpening tool part 108 is rotatably actuated by the drive mechanism 104 generally in the same manner as in the known Dremel tools.

One of the characteristics of the hook sharpener 16 is the ability to use different types of parts for sharpening the hooks. Figure 1, for example, shows the assembled sharpening part 108 which has diamond abrasive particles and is of a generally truncated cone shape. Figure 2 shows the separated part 108. Figures 1 and 2 show an additional part 110 that is cylindrical in shape and has an abrasive stone surface. A third part illustrated is part 112, which is generally cylindrical in shape with a small diameter, narrows slightly at its end and is made of diamond abrasive particles. Each of the parts 108, 110 and 112 works to obtain a different sharpening action that can be used for different types of hooks. Other types of parts can also be used. Conveniently, the parts are mounted on a sliding extension 116 of the cover 114 to detachably hold the parts. Cap 114 also includes a closure portion 118.

Conveniently, as shown in Figure 1, the hook sharpener 16 is removably and slidably inserted into a compartment 120 in the lower housing 50 of the knife sharpener housing 12. The knife sharpener housing 12 has a recess on its side so that the cover 114 can slide into the recess until the closure 118 enters and fits comfortably in the open end of the compartment 120. The cover 114 conforms to the shape of the lower housing 50 of the housing. Figures 8 and 12 show the cover 114 mounted in place with a direction arrow indicating the direction of movement to remove the cover 114 and allow the hook sharpener 16 to be removed from the compartment 120.

An additional feature is to provide knife sharpener 12 with the ability to be operated where AC power is not available. Figure 2 illustrates the power port 122 that is electrically connected to the motor 18. The power port 122, optionally, can be powered by an AC power cord 126 that could be plugged into a conventional outlet. Alternatively, the power port 122 could be powered by a DC power cord 128 that could be connected to, for example, a cigarette lighter in a vehicle. Therefore, if a conventional outlet is not readily available, the power cord 128 would be connected to the power port 122. Alternatively, when a conventional outlet is available, the AC power cord 126 could be connected to the port Power 122.

One of the features is the use of a single circuitry to start the motor 18 when DC power is used. A 12 VDC switching power supply is used to take advantage of its economy and availability. However, the maximum current of the power supply is limited, such as 2.5 amps. If more current is attracted, a safety overload is tripped that cuts off the power. The motor 18 for the knife sharpener 12 would run at a current below the maximum, such as an average of 1.5 amps. However, in order to start the motor 18 at full voltage, a greater number of amps, such as 7 amps, would be necessary, which exceeds the maximum current for the operation of the motor 18. In order to start motor 18 in this Higher current, such as 7 amps, a printed circuit board (PCB) uses pulsation technology (pulse width modulation). A circuit is used to create a high frequency pulse waveform that can control the voltage and current supplied to the motor 18. This is a technique commonly used in industrial applications. Figure 23 illustrates a block diagram for the motor starter PCB 18 after the DC power cable 128 is connected to the power port 122. The switch 130 is of Figures 1,2 and 23 on. The various functions of the control and the monitor (which include the safety lock to cut the power supply) illustrated in Figure 23 below, ensure that the motor 18

It can be started correctly and then run at a current below its maximum.

The use of pulse technology has advantages over other existing technologies. For example, capacitors can be used to store the voltage and provide a pulse during engine starting. It is difficult, however, to find a value or size of the capacitor that works effectively for the motor 18 of the knife sharpener 5 12. A resistor in a series can also be used to start a motor. The resistance, however, has a major disadvantage that continues to limit engine power and consumes energy, even after the engine is started. NTC thermistors have a resistance that changes with heat and time. These electronic components begin with a value of the initial resistance and the decrease in resistance during use. Their main disadvantage is that they require several minutes of recovery time to restart the engine. With respect to a multi-position starter switch, a momentary switch can be used to start the motor with a resistor and then change the output resistance for operation in a stable state. This has a main disadvantage, however, that it requires the user to know the proper engine speed threshold before switching to normal operating speed. These inconveniences are overcome by the use of pulsation technology. While the present invention is in particular adapted for use by fishermen or for other marine purposes, the concepts of this invention can also be used for other types of sharpener.

Claims (10)

5 10 fifteen twenty 25 30 35 40 1. A hand-operated sharpener (14) comprising a base (52), a hollow housing housing (54) mounted on said base (52), an extension of the housing (55) above said base (52) , a guide surface (58) in said housing extension (55), characterized in that it further comprises a carousel (60) in said housing extension (55), said carousel (60) has a rotating cylinder (68), a first abrasive pad (70, 72) mounted on said cylinder (68), a second abrasive pad (70, 72) mounted on said cylinder (68), the rotation of said cylinder (68) selectively disposes each of said first abrasive pad (70, 72) and said second abrasive pad (70, 72) adjacent to said guide surface (58), and each of said first abrasive pad (70, 72) and said second abrasive pad (70, 72 ) differs from one another in abrasive characteristics. 2. The sharpener (14) of Claim 1, wherein each of said first abrasive pad (70, 72) and said second abrasive pad (70, 72) includes a flat portion located adjacent to said guide surface (58 ) when said respective first abrasive pad (70, 72) and said second abrasive pad (70, 72) are selectively arranged on said guide surface (58), and each of said first abrasive pad (70, 72) and said second abrasive pad (70, 72) mounted in different angular orientations with respect to said guide surface (58). 3. The sharpener (14) of Claim 2, wherein said cylinder (68) includes an upper flange extending outward (71) and a lower flange extending outward (69) separated from said upper flange ( 71), a set of grooves (73) on the lower surface of said upper flange (71), a set of grooves (73) on the upper surface of said lower flange (69) corresponding to said grooves (73) in said upper flange (71), at least one of said grooves (73, 92) in said lower flange (69) is displaced from its groove (73) of the corresponding upper flange (71) and each of said pads (70, 72) is mounted in a respective slot (73) of said upper flange (71) and a corresponding slot (73) of said lower flange (69) to keep said pad (70, 72) in a flat condition and in an angular orientation preset 4. The sharpener (14) of Claim 1, wherein a thumb wheel (66) is mounted on said cylinder (68), said cylinder (68) includes an internally threaded hole, and a threaded rod (74) engaged by threading into said cylinder hole (68) to move said abrasive pads (70, 72) up / down according to the rotation of said thumb wheel (66). 5. The sharpener (14) of Claim 1, which includes the locking projections (94) on opposite sides of said sharpener base (52) and said casing (54) and said sharpener base (52) is made of a rigid but deformable elastic material such that after compression of said housing (54), said locking projections (94) move inwards. 6. The sharpener (14) of Claim 1, which includes a magnet (84) located below said guide surface (58). 7. The sharpener (14) of Claim 1, wherein said pads (70, 72) are magnetized. 8. The sharpener (14) of Claim 1, which includes a retaining spring (86) mounted above said guide surface (58) and extending towards but separated from said guide surface (58) to provide a elastic force against a cutting instrument that is being sharpened. 9. The sharpener (14) of Claim 1, which includes a wedge (88) mounted on said guide surface (58) to form a substitute guide surface (88). 10. The sharpener (14) of Claim 9, wherein said wedge (88) is adjustable to accommodate different sharpening angles.